In the pursuit of ever higher efficiencies, gas turbine manufacturers have long relied on higher and higher turbine inlet temperatures to provide boosts to overall engine performance. In typical modern engine applications, the gas path temperatures within the turbine exceed the melting point of the component constituent materials. To combat the demanding temperatures, dedicated cooling air may be extracted from the compressor and used to cool the gas path components, incurring significant cycle penalties. Cooled components may include, for example, rotating blades and stator vanes in the turbine.
One mechanism used to cool turbine airfoils includes utilizing internal cooling circuits and/or a baffle. Typically, numerous film cooling holes and high volumes of cooling fluid are required to provide the needed airfoil cooling. To augment the internal cooling, a number of interior treatments to the passages have been implemented including pedestals, air jet impingement, and turbulator treatments for the walls.
A limitation in the use of pins and pedestals in internal cavities is a manufacturing limitation. Namely, internal features may be kept in a normal direction toward the pull-plane of the casting dies typically used to generate cooled components. In the case of pedestals in stamped metallic cores, this means that the pedestals may be normal to the cavity flow direction commensurate with the action of pressing the core.